Double-acting refrigerant compressor

ABSTRACT

A main stopper recess  70  for supporting a protuberance  21   d  of an inlet valve  21  during the suction stroke and sub-stopper recesses  71, 72  for supporting side protuberances  21   e,    21   f  of the inlet valve  21  during the suction stroke are formed at an opening edge  6   a  of the cylinder bore. Due to this construction, even when the area of inlet port  15  is increased, large twisting load is not applied to the inlet valve  21  during the suction stroke, and vibrations of the inlet valve  21  are prevented.

TECHNICAL FIELD

[0001] This invention relates to a reciprocating refrigerant compressor used as a refrigerant compressor for an automotive air conditioner, and more particularly to a reciprocating refrigerant compressor of a type in which pistons reciprocate, such as a wobble plate compressor and a swash plate compressor.

BACKGROUND ART

[0002] A wobble plate compressor includes a cylinder block having a plurality of cylinder bores, a plurality of pistons for reciprocating within the respective cylinder bores, a cylinder head secured to an end face of the cylinder block via a valve plate, and a plurality of inlet valves for opening and closing a plurality of inlet ports formed through the valve plate.

[0003] Within the cylinders are formed compression chambers, respectively, and the volume of each compression chamber varies with the motion of a piston associated therewith.

[0004] The cylinder head has a suction chamber formed therein for receiving low-pressure refrigerant gas flowing therein from an evaporator side.

[0005] The number of the inlet valves and the number of the inlet ports form d through th valve plate are equal to the number of the cylinder bores, similarly to the number of the compression chambers and the number of the pistons.

[0006] The suction chamber communicates with the compression chambers via the inlet ports.

[0007] During the suction stroke, as the volume of a compression chamber progressively increases, the inlet valve is bent toward the compression chamber side to open the inlet port, via which refrigerant gas in the suction chamber is drawn into the compression chamber.

[0008]FIG. 13 is a fragmentary enlarged plan view of a valve plate of a conventional wobble plate compressor.

[0009] A valve plate 302 is formed with inlet ports 315, and outlet ports 316 are formed inward of the inlet ports 315 (radially inward in the valve plate 302). Further, the inlet ports 315 and the outlet ports 316 are located inward of respective opening edges 306 a of the cylinder bores. An inlet valve 321 is formed with a hole 363, such that the outlet port 316 is prevented from being closed by the inlet valve 321.

[0010] The opening edge 306 a of the cylinder bore is formed with a stopper recess 370 at a location opposed to a protuberance 321 d of the inlet valve 321.

[0011] As the piston moves toward the bottom dead center position during the suction stroke, the difference in pressure between the compression chamber and the suction chamber is increased, whereby the inlet valve 321 is bent toward the compression chamber side to open the inlet port 315, via which refrigerant gas in the suction chamber is drawn into the compression chamber. At this time, the protuberance 321 d of the inlet valve 321 abuts on the stopper recess 370, which limits the bend of th inlet valve 321.

[0012] The dimension of depth of the stopper recess 370 (length from an end face of the cylinder block to the bottom surface of the stopper recess 370) is configured to be small to thereby reduce the suction pulsation.

[0013] As the piston moves toward the top dead center position during the compression stroke, the volume of the compression chamber is progressively reduced to increase the pressure in the compression chamber. At this time, the inlet valve 321 is brought into intimate contact with the valve plate 302 by high pressure to close the inlet port 315.

[0014] However, if the dimension of depth of the stopper recess 370 is small, the suction efficiency is lowered, which degrades the performance of the refrigerant compressor.

[0015] To improve the performance of the refrigerant compressor, it is necessary to increase the area of an opening formed during suction of refrigerant. To meet this requirement, it is necessary to increase the area of the inlet port 315. If the area of the inlet port 315 is increased, it is necessary to enlarge the inlet valve 321 accordingly.

[0016]FIG. 14 is a perspective view showing a valve plate and a valve sheet proposed by the present inventors. FIG. 15 is a plan view of the valve plate shown in FIG. 14. FIG. 16 is a partial view of an end face of a cylinder block and the valve sheet as viewed from the valve sheet side. FIG. 17 is a cross-sectional view tak n on line XVII-XVII of FIG. 16, in which FIG. 17(a) is a view showing a state befor an inlet valve is opened, and FIG. 17(b) is a view showing a state after the inlet valve is opened. FIG. 18 is a fragmentary enlarged perspective view of the cylinder block.

[0017] As shown in FIG. 14, the inlet port 15 and the inlet valve 421 are larger than the inlet port 315 and the inlet valve 321, respectively.

[0018] The inlet port 15 bulges out arcuately along the opening edge 406 a of the cylinder bore 406. In the same manner as the inlet port 15, a port-blocking portion 421 a of the inlet valve 421 bulges out arcuately along the opening edge 406 a.

[0019] This wobble plate compressor has features in common with the wobble plate compressor shown in FIG. 13 in that the outlet port 16 is formed inward of the inlet port 15, that the inlet valve 421 is formed with the hole 463, and that the cylinder block 401 is formed with the stopper recess 470 opposed to the protuberance 421 d of the inlet valve 421.

[0020] If the area of the inlet port 15 is increased, the amount of refrigerant gas flowing into the compression chamber 460 during high-load operation is increased, so that the opposite ends of the port-blocking portion 421 a of the inlet valve 421 is largely bent into the compression chamber 460 (see FIG. 17(b)), which causes excessively large twisting load to act on root portions 421 c, 421 d of the inlet valve 421.

[0021] This results in the problem of deformation or breakage of the inlet valve 421, and low-pressure pulsation.

[0022] It is an object of the invention to provide a reciprocating refrigerant compressor that is capable of preventing deformation and breakage of inlet valves and low-pressure pulsation, which might occur when the areas of the inlet ports are increased.

DISCLOSURE OF THE INVENTION

[0023] To attain the above object, a reciprocating refrigerant compressor according the present invention includes a cylinder block having a plurality of cylinder bores formed therein, a cylinder head secured to an end face of the cylinder block via a valve plate, a low-pressure chamber formed within the cylinder head, a plurality of inlet ports formed through the valve plate, for communicating between the low-pressure chamber and the cylinder bores, and a plurality of inlet valves for opening and closing the inlet ports, the inlet valves each having an inlet port-blocking portion formed to have a generally arcuate shape, wherein a main stopper recess is formed at an opening edge of each cylinder bore of the cylinder block, for supporting, during an suction stroke, a central protuberance formed in a central portion of the inlet port-blocking portion of the inlet valve with respect to a direction along an arc of the inlet port-blocking portion in a manner protruding outward in a radial direction of the cylinder bore, and a plurality of sub-stopper recesses are formed at the opening edge of each cylinder bore of the cylinder block, for supporting, during the suction stroke, side protuberances, respectively, which are formed at opposite ends of the inlet port-blocking portion of the inlet valve with respect to the direction along the arc of the inl t port-blocking portion in a manner protruding outward in a radial direction of the cylinder bore.

[0024] Even when the area of the inlet port is increased, not large twisting motion is applied to the inlet valve during the suction stroke, and vibrations of the inlet valve are prevented, which makes it possible to prevent deformation and breakage of the inlet valve and low-pressure pulsation.

[0025] Preferably, bottom surfaces of the sub-stopper recesses are sloped.

[0026] When the inlet valve is bent toward the compression chamber side during the suction stroke, the side protuberances come into collision with the sub-stopper recesses. However, at this time, the side protuberances are brought into surface contact with the bottom surfaces of the sub-stopper recesses, which lessens the impact of the collision and suppresses noise. Further, when the inlet port is bent, the inlet port-blocking portion is largely bowed inward at the approximately central portion thereof, which makes it easier to draw in refrigerant gas, thereby further enhancing the suction efficiency.

[0027] Preferably, depth of the sub-stopper recesses is made larger than depth of the main stopper recess.

[0028] When the inlet valve is bent toward the compression chamber side during the suction stroke, first, the central protuberance comes into collision with the main stopper recess, thereby being restricted in lift thereof, and then the side protuberances come into collision with the sub-stopp r recess s, thereby being restricted in lift thereof. Thus, the timing in which the lift of th side protuberances is restricted is d layed relative to the timing in which the lift of the central protuberance is restricted, which makes it easy to draw in refrigerant.

[0029] Preferably, bottom surfaces of the sub-stopper recesses are sloped, and depth of the sub-stopper recesses is made larger than depth of the main stopper recess.

[0030] Preferably, depth of the sub-stopper recesses is made smaller than depth of the main stopper recess.

[0031] When the inlet valve is bent toward the compression chamber side during the suction stroke, first, the side protuberances come into collision with the sub-stopper recesses, thereby being restricted in lift thereof, and then the central protuberance comes into collision with the main stopper recess, thereby being restricted in lift thereof. Thus, the lift of the side protuberances is restricted before the lift of the central protuberance is restricted, which prevents vibrations of the inlet valves more positively.

[0032] Preferably, bottom surfaces of the sub-stopper recesses are sloped, and depth of the sub-stopper recesses is made smaller than depth of the main stopper recess.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 is a partial view of an end face of a cylinder block and a valve sheet of a wobble plate compressor according to a first embodiment of the present invention, as viewed from the valve sheet side;

[0034]FIG. 2 is a cross-sectional view taken on line II-II of FIG. 1, in which FIG. 2(a) is a view showing a state before an inlet valve is opened, and FIG. 2(b) is a view showing a state after the inlet valve is opened;

[0035]FIG. 3 is a perspective view showing the whole of the valve plate and the valve sheet;

[0036]FIG. 4 is a plan view showing the whole of the valve plate;

[0037]FIG. 5 is a fragmentary enlarged perspective view of the cylinder block of the wobble plate compressor according to the first embodiment of the present invention;

[0038]FIG. 6 is a cross-sectional view showing the wobble plate compressor according to the first embodiment of the present invention;

[0039]FIG. 7 is a fragmentary enlarged perspective view of a cylinder block of a wobble plate compressor according to a second embodiment of the present invention;

[0040]FIG. 8 is a fragmentary enlarged cross-sectional view useful for explaining the relationship between an inlet valve and protuberances of the cylinder block, in which FIG. 8(a) is a view showing a state before the inlet valve is opened, and FIG. 8(b) is a view showing a state after the inlet valve is opened;

[0041]FIG. 9 is a cross-sectional view of the inlet valve after it is opened, as viewed from a different angle;

[0042]FIG. 10 is a fragmentary enlarged perspective view of a cylinder block of a wobble plate compressor according to a third embodiment of the present invention;

[0043]FIG. 11 is a fragmentary enlarged cross-sectional view useful for explaining the relationship between an inlet valve and protuberances of the cylinder block, in which FIG. 11(a) is a view showing a state before the inlet valve is opened, and FIG. 11(b) is a view showing a state after the inlet valv is op ned;

[0044]FIG. 12 is a cross-s ctional view of the inlet valve after it is opened, as viewed from a different angle;

[0045]FIG. 13 is a fragmentary enlarged plan view of a valve plate of a conventional wobble plate compressor;

[0046]FIG. 14 is a perspective view showing a valve plate and a valve sheet proposed by the present inventors;

[0047]FIG. 15 is a plan view of the valve plate shown in FIG. 14;

[0048]FIG. 16 is a partial view of an end face of a cylinder block and the valve sheet as viewed from the valve sheet side;

[0049]FIG. 17 is a cross-sectional view taken on line XVII-XVII of FIG. 16, in which FIG. 17(a) is a view showing a state before an inlet valve is opened, and FIG. 17(b) is a view showing a state after the inlet valve is opened; and

[0050]FIG. 18 is a fragmentary enlarged perspective view of the cylinder block.

BEST MODE FOR CARRYING OUT THE INVENTION

[0051] The invention will now be described in detail with reference to drawings showing preferred embodiments thereof.

[0052]FIG. 6 is a cross-sectional view showing a wobble plate compressor according to a first embodiment of the present invention. FIG. 1 is a partial view of an end face of a cylinder block and a valve sheet of the wobble plate compressor, as viewed from the valve sheet side. FIG. 2 is a cross-sectional view taken on line II-II of FIG. 1, in which FIG. 2(a) is a view showing a state before an inlet valve is op ned, and FIG. 2(b) is a view showing a state after the inlet valve is op ned. FIG. 3 is a perspective view showing th whole of the valve plate and the valve sheet. FIG. 4 is a plan view showing the whole of the valve plate, and FIG. 5 is a fragmentary enlarged perspective view of the cylinder block.

[0053] This compressor has a cylinder block 1 having one end thereof secured to a rear head (cylinder head) 3 via a valve plate 2 and the other end thereof secured to a front head 4.

[0054] The cylinder block 1 has a plurality of cylinder bores 6 axially extending therethrough at predetermined circumferential intervals about the shaft 5. Each cylinder bore 6 has a piston 7 slidably received therein. The cylinder bore 6 defines a compression chamber 60 therein, the volume of which is changed with motion of the piston 7. An opening edge (cylinder bore opening edge) 6 a of the cylinder bore 6 is formed with a main stopper recess 70 and sub-stopper recesses 71, 72, as shown in FIG. 1. The stopper recesses 70, 71, 72 limit the amount of bend (opening degree) of the inlet valve 21.

[0055] Within the front head 4, there is formed a crankcase 8 within which a wobble plate 10 is accommodated for wobbling motion performed about a hinge ball 9 in a manner interlocked with the shaft 5.

[0056] Within the rear head 3, there are formed a discharge chamber 12 and a suction chamber 13 located around the discharge chamber 12.

[0057] The valve plate 2 is formed with a plurality of outlet ports 16 for communicating between the cylinder bores 6 and the discharge chamber 12, and a plurality of inlet ports 15 for communicating between the cylinder bore 6 and the suction chamber 13, at predetermined circumfer ntial intervals. The outlet ports 16 ar opened and closed by the outlet valves 17, and the outlet valves 17 are fixed to the rear head-side end face of the valve plate 2 together with a valve retainer 18 by a rivet 19. Further, inlet ports 15 are opened and closed by the inlet valves 21, and the inlet valves 21 are disposed between the valve plate 2 and the cylinder block 1. The discharge chamber 12 and the crankcase 8 are communicated with each other via a passage 79 and an orifice 80.

[0058] The respective numbers of the inlet valves 21, the outlet valves 17, the inlet ports 15, the outlet ports 16, and the compression chambers 60 are equal to the number (5 in this embodiment) of the cylinder bores 6.

[0059] As shown in FIGS. 1 to 3, the inlet port 15 and the outlet port 16 are located, inward of the opening edge 6 a of the cylinder bore 6. Further, the inlet ports 15 are located outward of the outlet ports 16 (radially outward in the valve plate 2). The five inlet ports 15 each largely bulge out from support centers C1, C2 (see FIG. 1), and accordingly, an inlet port-blocking portion 21 a of the inlet valve 21 is larger than an inlet port-blocking portion 321 a of the inlet valve 321 of the prior art. It should be noted that the support center C1 is defined as a straight line connecting between a supported point of the central protuberance 21 d and a supported point of a root portion 21 b, and the support center C2 is defined as a straight line connecting between the supported point of the central protuberance 21 d and a supported point of a root portion 21 c.

[0060] As shown is FIG. 3, the five inlet valves 21 are int grally formed with a valve she t 62. Each inlet valve 21 is formed with a hole 63, which pr vents the outlet port 16 from being closed by the inlet valve 21. Each inlet valve 21 is comprised of three protuberances 21 d, 21 e, 21 f, one inlet port-blocking portion 21 a, and two root portions 21 b, 21 c. The inlet port-blocking portion 21 a of the inlet valve 21 is formed to have a generally arcuate shape in a manner adapted to the shape of the inlet port 15. The central protuberance 21 d is provided in a central portion of the inlet port-blocking portion 21 a with respect to a direction of the arc thereof, and the side protuberances 21 e, 21 f are provided at opposite ends of the inlet port-blocking portion 21 a with respect to the direction of the arc of the same. The protuberances 21 d, 21 e, 21 f are each protruded radially outward from the opening edge 6 a of the cylinder bore 6 such that the central protuberance 21 d is opposed to the main stopper recess 70 in the direction of the central axis of the cylinder bore 6, while the side protuberances 21 e, 21 f are opposed to the sub-stopper recesses 71, 72 in the direction of the central axis of the cylinder bore 6. The side protuberances 21 e, 21 f are located outward of the support centers C1, C2. The two root portions 21 b, 21 c support the inlet port-blocking portion 21 a.

[0061] The cylinder block 1 is formed with a communication passage 31 communicating between the suction chamber 13 and the crankcase 8, and a pressure control valve 32 is arranged across an intermediate portion of the communication passage 31, for control of pressure in the suction chamber 13 and pressure in the crankcase 8.

[0062] Further, the front-side end of the shaft 5 is rotatably supported by a radial bearing 26 arranged in th front head 4, and the rear-sid end of the shaft 5 is rotatably supported by a radial bearing 24 and a thrust bearing 25. The shaft 5 has a thrust flange 40 fixed thereon, and a drive hub 41 mounted thereon via a hinge ball 9 which is axially slidable. The thrust flange 40 is supported on the inner wall of the front head 4 via a thrust bearing 33. A portion of the thrust flange 40 and a portion of the drive hub 41 are connected by a linkage 42 via which the rotation of the shaft 5 is transmitted from the thrust flange 40 to the drive hub 41. The wobble plate 10 is relatively rotatably mounted on the drive hub 41 via a radial bearing 27 and a thrust bearing 28. The wobble plate 10 is connected to the pistons via connecting rods 11.

[0063] Between the hinge ball 9 and a boss 40 b of the thrust flange 40, a coil spring 44 is interposed as a destroke spring, and the hinge ball 9 is urged toward the cylinder block 1 by the coil spring 44.

[0064] Further, a fixed washer 45 is fixedly fitted on the shaft 5 at a location toward the cylinder block side, and between the fixed wash 45 and the hinge ball 9, a plurality of curved springs 46 and a coil spring 47 as destroke springs are interposed in series, for urging the hinge ball 9 toward the thrust flange 40.

[0065] Next, the operation of this wobble plate compressor will be described.

[0066] As torque of an engine, not shown, installed on a vehicle, not shown, is transmitted to the shaft 5, the thrust flange 40 and the drive hub 41 rotate together with the shaft 5, which causes the wobble plate 10 to wobble about the hinge ball 9. The wobbling motion is transmitted to th pistons 7 via the connecting rods 11, whereby the wobbling motion is converted into the linear reciprocating motion of each piston 7. As the piston 7 reciprocates in the cylinder bore 6, the volume of the compression chamber 60 changes, which sequentially causes the suction, compression, and delivery of refrigerant gas, whereby high-pressure refrigerant gas is delivered in an amount corresponding to an angle of inclination of the wobble plate 10.

[0067] When thermal load on the compressor decreases and the pressure control valve 32 closes the communication passage 31 to increase the pressure in the crankcase 8, the angle of inclination of the wobble plate 10 becomes smaller, so that the length of stroke of the piston 7 is decreased to reduce the displacement of the compressor. On the other hand, when thermal load on the compressor increases and the pressure control valve 32 opens the communication passage 31 to reduce the pressure in the crankcase 8, the angle of inclination of the wobble plate 10 becomes larger, whereby the length of stroke of the piston 7 is increased to increase the displacement of the compressor.

[0068] In the suction stroke, as the piston 7 moves to the bottom dead center position, the difference between pressure in the compression chamber 60 and pressure in the suction chamber 13 is increased, so that the inlet valve 21 is bent into the compression chamber 60 to open the inlet port 15, via which the refrigerant gas in the suction chamber 13 is drawn into the compression chamber 60. As described above, each of the five inlet ports 15 largely bulges out from the support centers C1, C2, and the area thereof is larger than the area of the inl t port 315 of the prior art, which makes the suction efficiency higher than the prior art.

[0069] When the inlet valve 21 is bent into the compression chamber 60, as shown in FIG. 2(b), the central protuberance 21 d is supported by the main stopper recess 70, and the side protuberances 21 e, 21 f are supported by the sub-stopper recesses 71, 72. This prevents large twisting load from being applied to the inlet valve 21, and the inlet valve 21 from performing vibrations (so-called flapping).

[0070] Further, in the compression stroke, as the piston 7 moves to the top dead center position, the volume of the compression chamber 60 is progressively reduced to increase the pressure in the compression chamber 60. At this time, the inlet valve 21 keeps the inlet port 15 closed and the outlet port 17 keeps the outlet port 16 closed. In the delivery stroke, the volume of the compression chamber 60 becomes minimum, and the pressure in the compression chamber 60 becomes maximum. When there is produced a predetermined differential pressure between the compression chamber 60 and the discharge chamber 12, the outlet valve 17 is bent into the discharge chamber 60 to open the outlet port 16. At this time, the inlet valve 21 keeps the inlet port 15 closed.

[0071] According to the first embodiment, even when the area of the inlet port 15 is increased, large twisting motion is not applied to the inlet valve 21 during the suction stroke, and vibrations of the inlet valve 21 are prevented, which makes it possible to prevent deformation and breakage of the inlet valve 21 and low-pressure pulsation.

[0072]FIG. 7 is a fragmentary enlarged perspective view of a cylinder block of a wobble plat compressor according to a second embodiment of the present invention. FIG. 8 is a fragmentary enlarged cross-sectional view useful for explaining the relationship between an inlet valve and protuberances of the cylinder block, in which FIG. 8(a) is a view showing a state before the inlet valve is opened, and FIG. 8(b) is a view showing a state after the inlet valve is opened. FIG. 9 is a cross-sectional view of the inlet valve after it is opened, as viewed from a different angle. The construction of the wobble plate compressor is identical to that of the wobble plate compressor according to the first embodiment except for the cylinder block, and therefore description thereof is omitted.

[0073] This embodiment is distinguished from the first embodiment in that respective bottom surfaces 171 a, 172 a of sub-stopper recesses 171, 172 are sloped.

[0074] The respective bottom surfaces 171 a, 172 a of the sub-stopper recesses 171, 172 are sloped toward the center of the inlet port 15.

[0075] When the inlet valve 21 is bent into the compression chamber 60, the two side protuberances 21 e, 21 f come into collision with the bottom surfaces 171 a, 172 a of the sub-stopper recesses 171, 172. At this time, the side protuberances 21 e, 21 f are brought into surface contact with the bottom surfaces 171 a, 172 a of the sub-stopper recesses 171, 172, which lessens the impact of the collision.

[0076] Further, when the inlet port 21 is bent, the inlet port-blocking portion 21 a is largely bowed inward at the approximately central portion thereof, which makes it easy to draw in refrigerant gas, thereby further enhancing th suction efficiency.

[0077] According to the second embodim nt, it is possible to obtain the same advantageous effects as provided by the first embodiment, as well as lessen the impact of collision of the side protuberances 21 e, 21 f of the inlet valve 21 against the bottom surfaces 171 a, 172 a of the sub-stopper recesses 171, 172, thereby suppressing noise, and further increasing the suction efficiency by the increase in the bending of the inlet valve 21.

[0078]FIG. 10 is a fragmentary enlarged view of a cylinder block of a wobble plate compressor according to a third embodiment of the present invention. FIG. 11 is a fragmentary enlarged cross-sectional view useful for explaining the relationship between an inlet valve and protuberances of the cylinder block, in which FIG. 11(a) is a view showing a state before the inlet valve is opened, and FIG. 11(b) is a view showing a state after the inlet valve is opened. FIG. 12 is a cross-sectional view of the inlet valve after it is opened, as viewed from a different angle. The construction of this wobble plate compressor is identical to that of the wobble plate compressor according to the first embodiment except for the cylinder block, and therefore description thereof is omitted.

[0079] This embodiment has features in common with the second embodiment in that bottom surfaces 271 a, 272 a of sub-stopper surfaces 271, 272 of a cylinder block 201 are sloped toward the center of the inlet port 15, but is different from the second embodiment in that the sub-stopper recesses 271, 272 are located little closer to the central portion of the cylinder block 201 than the sub-stopper recesses 171, 172 of the second embodiment are.

[0080] According to the third embodim nt, it is possible to obtain the same advantageous effects as provided by the second embodiment.

[0081] In the above embodiments, the relationship between the depth of the main stopper recesses 70, 170, 270 and that of the sub-stopper recesses 71, 72, 171, 172, 271, 272 is not particularly specified, it is possible to configure, as other embodiments, that the depth of the sub-stopper recesses 71, 72, 171, 172, 271, 272 is made smaller than that of the main stopper recesses 70, 170, 270. This configuration causes, during the suction stroke, first, the two side protuberances 21 e, 21 f to collide against the sub-stopper recesses 71, 72, 171, 172, 271, 272, and then the central protuberance 21 d to collide against the main stopper recesses 70, 170, 270, which positively suppresses the vibrations of the inlet valve 21.

[0082] Inversely, the depth of the sub-stopper recesses 71, 72, 171, 172, 271, 272 may be made larger than that of the main stopper recesses 70, 170, 270. This configuration causes, during the suction stroke, first, the central protuberance 21 d to collide against the main stopper recesses 70, 170, 270, and then the two side protuberances 21 e, 21 f to collide against the sub-stopper recesses 71, 72, 171, 172, 271, 272. The timing in which the lift of the side protuberances 21 e, 21 f is restricted is delayed relative to the timing in which the lift of the central protuberance 21 d is restricted, which makes it easy to draw in refrigerant.

[0083] In the above embodiments, the two side protuberances 21 e, 21 f of the inlet valve 21 are provided at opposite ends of the inlet valve 21 with respect to a direction of the arc thereof, one for each, resp etively, and the two sub-stopper recesses 71 and 72, 171 and 172, 271 and 272 are formed in the cylinder block 1, 101, 201, respectively, in accordance therewith. However, when the side protuberances 21 e, 21 f are provided at the opposite ends of the inlet valve 21 with respect to the direction of the arc thereof, two or more for each, respectively, two or more sub-stopper recesses are formed in accordance therewith.

[0084] Although in the above embodiments, as an example of the reciprocating refrigerant compressor, the wobble plate compressor is described, the scope of the present invention is not limited to this, but the present invention can be applied to other reciprocating compressors, such as a swash plate compressor.

INDUSTRIAL APPLICABILITY

[0085] As described heretofore, the reciprocating refrigerant compressor according to the present invention is useful as a refrigerant compressor for an automotive air conditioner, and according to this reciprocating refrigerant compressor, even when the area of inlet ports is increased, large twisting load is not applied to the inlet valves during the suction stroke, and vibrations of the inlet valves are prevented. 

1. A reciprocating refrigerant compressor including: a cylinder block having a plurality of cylinder bores formed therein, a cylinder head secured to an end face of said cylinder block via a valve plate, a low-pressure chamber formed within said cylinder head, a plurality of inlet ports formed through said valve plate, for communicating between said low-pressure chamber and said cylinder bores, and a plurality of inlet valves for opening and closing said inlet ports, said inlet valves each having an inlet port-blocking portion formed to have a generally arcuate shape, wherein a main stopper recesses is formed at an opening edge of each cylinder bore of said cylinder block, for supporting, during an suction stroke, a central protuberance formed in a central portion of said inlet port-blocking portion of said inlet valve with respect to a direction along an arc of said inlet port-blocking portion in a manner protruding outward in a radial direction of said cylinder bore; and wherein a plurality of sub-stopper recesses are formed at the opening edge of each cylinder bore of said cylinder block, for supporting, during the suction stroke, side protuberances, respectively, which are formed at opposite ends of said inlet port-blocking portion of said inlet valve with respect to the direction along the arc of said inlet port-blocking portion in a manner protruding outward in a radial direction of said cylinder bore.
 2. A reciprocating refrigerant compressor according to claim 1, wherein bottom surfaces of said sub-stopper recesses are sloped.
 3. A reciprocating refrigerant compressor according to claim 1, wherein depth of said sub-stopper recesses is made larger than depth of said main stopper recess.
 4. A reciprocating refrigerant compressor according to claim 1, wherein bottom surfaces of said sub-stopper recesses are sloped, and wherein depth of said sub-stopper recesses is made larger than depth of said main stopper recess.
 5. A reciprocating refrigerant compressor according to claim 1, wherein depth of said sub-stopper recesses is made smaller than depth of said main stopper recess.
 6. A reciprocating refrigerant compressor according to claim 1, wherein bottom surfaces of said sub-stopper recesses are sloped, and wherein depth of said sub-stopper recesses is made smaller than depth of said main stopper recess. 